Your first point is incorrect. You think I am illegitimately counting neutral votes as "no" votes. I am not counting them as "no" votes, but they still destroy the consensus, as this illustration will show:

If in 2003, 97 physicists believe in the Big Bang theory, and 3 believe in the Steady State theory, there is a consensus of physicists in favour of the Big Bang theory.

If in 2007, 45 physicists believe in the Big Bang theory, 7 believe in the Steady State theory, and 48 believe that the empirical evidence and theoretical arguments are equally good for both theories, and cannot make up their minds, there is no longer any consensus of physicists in favour of the Big Bang theory.

Similarly, if 97% of scientists who discussed the question of AGW in 2003 believed in AGW, then a scientific consensus in favour of AGW existed in 2003. But if only 45% of the scientists who discussed the question of AGW in 2007 believed in AGW, and 7% disbelieved, and 48% thought that the evidence was inconclusive, then in 2007 no scientific consensus on AGW existed.

On your last point: Your method of combining the statistics of the two reports is astoundingly slipshod. We are not trying to determine the "average opinion" of scientists over two distinct time periods, based on the combined information in the two reports; we are trying to determine the change in opinion (if any) of scientists between the period ending in 2003 and the period ending in 2007. (Using your logic, if 80% of the American people were in favour of capital punishment in 2003, but only 40% of them were in favour of it in 2007, one could argue that, since the average is 60%, it is still the will of the American people in 2007 that capital punishment be retained. But the whole point would be that over the intervening four years the public opinion had shifted decisively against capital punishment. Similarly, what has to be determined is whether scientific opinion on AGW has shifted between 2003 and 2007.)

You seem to want to fight, tooth and nail, to prove that every single web site that disagrees with you is wrong, and that every single web site that agrees with you is right. In this case, regarding a study that I was not even defending, but merely trying to draw your attention to, in order to indicate evidence for another side, first you shot from the hip, seizing on the word "silent". Then, when I showed you that the word used was "neutral", not "silent", you tried other tactics to demolish the study. Instead of saying: "Gee, you are right, I did jump to conclusions when I inferred that "neutral" meant "silent" -- I should be more careful in the future! Maybe I should even track down and read some of the original papers, to see what sort of positions the study describes as "neutral", so I can better assess the validity of the study" --your first instinct was to redouble your assault on the enemy article. From the outset, you made not *inquiry* but *victory* your aim.

I was pointing out that it is this attitude, one possessed by culture warriors on *both* sides, that is the big problem. Nobody wants to *learn* anything new about global warming; they just want quotes and statistics with which to beat down the other side. You seem to see only the mote in the eye of the AGW skeptics, never the beam in your own. Your argumentative stance on AGW is simply the mirror image of the stance of the UD extremists that you have been railing against. That is why the AGW discussions are so intractable, because *both* sides are championed by people who put passionate commitment to prior positions above research and reasoned discussion.

First, there is no argument from silence, as you charge. The report did not say that 48% of the papers were "silent" about AGW. It said they were "neutral". It implied that AGW was discussed in those papers but that no side was taken. And if no side was taken, then that 48% of the papers cannot be counted in favour of the "consensus".

And these papers cannot be counted against consensus either.

That leaves the papers in favour of AGW as (at a maximum) 45%. So what happened to your 97% consensus among scientists, at least between 2003 and 2007? And, unless you have a new literature survey covering the last two years, how credible is your claim that it has bounced back to 97% now?

From the paper:

The analysis of 539 abstracts revealed that only a small part of papers identified
through this search mechanism contributed direct relevant data to the question of the consensus as set out above. [Note: In other words they were silent.]

The remainder have no bearing on climate change, or report the results of modeling, or review the literature, or provide commentary only.

For Oreskes the 25% were papers concerning methods or paleoclimate analysis. The 75% consensus affirmations were in the follow three categories: explicit endorsement, mitigation proposals, and evaluations of impacts. There were zero papers denying the consensus.

To count for example paleoclimate papers as buying or not buying into the consensus is just plain silly. It's silent and we can draw no conclusion. So, let's combine these two papers and count only those who explicitly or implicitly accept the consensus and explicitly or implicitly deny it.

1015 papers discussed in some way the consensus that "Human activities ... are modifying the concentration of atmospheric constituents ... that absorb or scatter radiant energy. ... [M]ost of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations". 978 (96%) of these explicitly or implicitly affirmed the consensus. 37 (4%) denied it. That's awfully close to the 97% AGU poll number from this year.

Rich Blinne
Member ASA

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Received on Mon Aug 24 06:51:41 2009